I would consider mass hysteria to be people duct taping their windows, standing in long lines outside of stores to try to get masks / hand sanitizer each morning, most people wearing masks all the time. I barely see 1 or 2 people with masks on on the subway every morning. I agree we are not at the point of "mass hysteria" right now.

I think there a a number of cases where cities and individuals are acting irrationally. The city of Monetary, CA, is refusing to disembark a cruise ship from San Francisco, CA, which boarded less than a day before 100 miles away. San Francisco has not had any cases of the virus and the ship screened passengers for fever.

There is also a lot of phobia and persecution of Asian Americans, despite the fact that most US cases are not Asian.

I do not think I have ever witnessed a reaction so extreme to a disease that is comparably mild (I understand that the elderly and immunocompromised are at higher risk, I am referring to young, able-bodied people). This applies to Germany as well as the US. I notice the effect it has on co-workers who tend to follow social media and are constantly panicking. Constantly discussing rumours from Twitter and even staying home because they are too afraid to leave the house. The unchecked spreading of news definitely seems to have an impact on the population's behaviour and I find it somewhat concerning to observe how easy it is to push people into a frenzy.

Maybe the perspective is also a bit skewed because people that post online often tend towards the paranoid and fearful type (somewhat of a conjecture), so there might be a self-perpetuating bias. Users that are not concerned do not bother to post so everyone just reads panicky posts.

True, but the general reaction was severe. Large events were cancelled and people quarantined.

To be honest, I am due for a skying trip in three weeks and the most fear I have is that they just shut down the location and don't let me in (bad) or don't let me out again (not that bad).

Look at /r/costco (for US) and you'll see the mild hysteria